1. Field of the Invention
The present invention relates to a trigger-type liquid sprayer (hereinafter also referred to simply as “liquid sprayer”) used by being attached to a container accommodating a liquid.
2. Description of Related Art
Various liquid sprayers provided with a liquid sprayer body having a nozzle, a spin element and a trigger lever and a shroud covering the liquid sprayer body and configured to spray a liquid from a spray hole of the nozzle through a pulling operation of the trigger lever have been proposed. A container provided with this type of liquid sprayer is widely used in recent years for containers containing hair styling spritz, air freshener and the like.
According to the art described in Japanese Patent Publication No. 2006-297219, the nozzle is positioned at a spraying position of a liquid by providing engagement projection portions engaged with each other which are provided between a nozzle and a spin element fitted therein, and operating by an operation plate rotating with the nozzle and engaging the engagement projection portions with each other.
However, with the above liquid sprayer, the nozzle is positioned at the spraying position of a liquid by rotating the operation plate and engaging the engagement projection portion formed on an inner face of the nozzle with the engagement projection portion on the spin element. Thus, there was a possibility that the engagement projection portions were chipped or broken by a rotary torque of the operation plate. Particularly, a fitting pressure is applied to the nozzle by fitting with other parts such as the spin element. The nozzle is also in contact with a contained liquid. Thus, environmental stress rupture may easily occur, and moreover, the rotary torque by the operation plate applied to the engagement projection portion may induce the environmental stress rupture. Also, since the engagement projection portions are engaged with each other inside the nozzle, there is a problem that the engaged state can not be easily checked from the outside.
Moreover, with this type of liquid sprayer, a piston is pushed into a cylinder by the pulling operation of a trigger lever so as to spray a liquid reserved in the cylinder from a spray hole, and thus it is necessary to exert a force in the horizontal direction with respect to the piston when the trigger lever is pulled. Therefore, in the conventional liquid sprayer, the rotation center of the trigger lever is separated from the nozzle and a distance between the rotation center and a point of application of force between the trigger lever and the piston is expanded so that a trajectory of the point of application is brought close to the horizontal and the force works onto the piston substantially horizontally.
On the other hand, as in a liquid sprayer described in Patent No. JP3243743, regulating means may be provided for preventing inadvertent spraying of contents due to erroneous operation of the trigger lever, and the above configuration was not preferable when this regulating means was to be added. Moreover, with this type of liquid sprayer, there has been a demand for size reduction so that the sprayer can be easily operated even by one hand.
In a liquid sprayer described in Japanese Patent Publication No. 2006-136803, a flow passage is formed by providing a groove communicating with each other at a fitting portion between a cylindrical portion extending to a side opposite to the liquid spraying direction with respect to the nozzle spray hole and a spin element so as to spray the liquid from the spray hole through the flow passage.
In this type of liquid sprayer, if a groove is provided at a fitting portion between a nozzle and a spin element, a sectional shape of the groove portion becomes uneven (thin). Thus, as with the liquid sprayer described in Japanese Patent Publication No. 2006-136803, it was easily damaged if a flow passage for the liquid formed at a specific rotating position by rotating the nozzle. Particularly, a fitting pressure is applied to the nozzle by being fitted with other parts such as the spin element and also in contact with a contained liquid, and thus, environmental stress rupture may easily occur and may induce the environmental stress rupture.
In a liquid sprayer described in Japanese Utility Model Publication No. 7-16051, a cylindrical body (spray cylinder) forming a spray path of contained liquid is supported by a main body portion of a body in a cantilever state and a spin element for applying a turning force to the contained liquid relating to spraying is usually attached at its tip end. However, a repulsion force (biasing force) of an elastic member biasing a piston toward the side of a trigger lever was often seen to act in a direction to push up the cylindrical body from the trigger lever through the spin element and cause flexural deformation on the cylindrical body.
In this case, since an installation position of the trigger lever is displaced upward, the piston is also lifted up at its front end portion, and though the piston should have been operated with the same shaft core as the shaft core of the cylinder when the pulling operation of the trigger lever is performed, the piston is diagonally pushed into the cylinder, which impairs reciprocation of the piston and prevents maintenance of a desired spraying form. Moreover, it is worrisome that sealing performance between the piston and the cylinder is lowered and a liquid leaks from between members.
Moreover, in this type of liquid sprayer, a method of fixing and holding the sprayer at a spout portion of a container by screwing through an intake (a base portion of the intake) at a lower end of a body is generally employed, and the sprayer is fixed and held by sandwiching the intake base portion between the spout portion of the container and the body at the lower end of the body. Thus, the lower end of the body is set with such a diameter that can be inserted through an opening of a cap, while its inside has to be thinned for connection with the base of the intake.
The thinning at the lower end portion of the body may cause flexural deformation to narrow a gap between the body front side (side where a spray nozzle is located) and a cap when a large impact is applied to the liquid sprayer due to inadvertent drop or the like and may damage the intake incorporated in the body, particularly the base portion of the intake or the cap screwed into the spout portion of the container through the intake, and it is also worrisome that the body may be easily removed from the intake.